The invention is in the field of exercising equipment. More particularly, the invention is a grip designed to be squeezed by a user""s hand to thereby improve the strength of the user""s hand, wrist and forearm. The grip has a semi-resilient structure in that once it is compressed by a user and undergoes a major deformation, it only partially returns to its former shape.
In the exercise field, there are numerous devices designed to help a user improve his or her grip strength and the muscles of the wrist and forearm. These devices usually can be classified in one of two categories. In the first category is the type of device that fits within a user""s hand and is squeezed by the user. In the second category is the type of hand exerciser that has one or more springs or elastic bands attached to a base. In the latter type of device, the user attempts to stretch the springs/bands with his or her fingers.
The squeezable type of device is typified by a ball or an ergonomically-shaped grip that the user can hold within a hand. Common rubber balls have been used as exercise grips for many years with varied amounts of success. The ergonomically-shaped grips normally include a shaped body that has indentations along a forward edge to partially receive each of a user""s long fingers.
The squeezable grips are manufactured from a rubber material that is fully resilient. The inherent resiliency of the material causes the grip to fully recover its original shape after being deformed by the user""s hand. Once the user has the grip within his or her hand, the user exercises by repeatedly squeezing and then releasing the grip. While exercising, the grip is normally maintained in a single position without any rotation caused by the user""s fingers.
The second type of exercise device normally includes a rigid, elongated base and a plurality of spacedly attached springs or elastic bands that are individually connected to the fingers of one of the user""s hands. The user places his or her hand onto the device and uses his or her fingertips to stretch the springs or elastic bands. When the user stops applying force, the springs or elastic bands return to their original length.
The invention is a ball-like grip that the user holds within one hand. The user applies pressure to the grip with his or her fingers to deform the grip""s shape. The grip has a structure that makes it semi-resilient in that when the user stops applying pressure to the grip after it has been significantly deformed, it only partially returns to the shape it had prior to the deformation.
To achieve this semi-resilient characteristic, the grip employs a particulate core surrounded by a resilient rubber covering. The core is comprised of a quantity of free particles intermixed with a dry lubricant powder. The lubricant allows the particles to slide over one another without damage and helps to reduce the internal resistance to sliding movement within the core.
The rubber covering exterior to the core is made of a latex rubber material that has a round shape when in an undeformed state. Whenever the core is deformed from a round shape, the rubber covering is stretched. When the deforming forces are released, the covering attempts to reshape the core back to a round shape. If the deformation has been considerable, the resiliency of the covering cannot fully overcome the core""s resistance to deformation. As a result, the grip only partially recovers its previous shape.
The semi-resilient characteristic of the grip significantly enhances its use. When the user initially compresses the grip, it will change its shape from a round ball to a disc-like shape. Once the user stops squeezing the grip, it partially springs back to its pre-deformation shape and becomes substantially egg-shaped. The new shape somewhat conforms to the shape of the user""s hand. At this point, the longitudinal axis of the grip extends across the user""s palm and is substantially perpendicular to the longitudinal axis of the user""s forearm.
The user can repeat the above exercise and again cause the grip to deform into a disc shape. When the user stops squeezing the grip, it will substantially return to the egg shape it had prior to the latest deformation. However, once the grip has been deformed and is egg-shaped, the user will normally rotate the grip ninety degrees so that its longitudinal axis is substantially parallel to the longitudinal axis of the user""s forearm. The user then squeezes the grip until it again assumes a disc shape. Upon release, it again assumes an egg shape that somewhat conforms to the user""s hand. The user may then rotate the grip another ninety degrees and repeat the squeezing motion.
The invention, by retaining some of the deformation caused by the user""s gripping action, lends itself to the manual manipulation described above. The user can, with every compression, change the shape of the grip. When the grip has become egg-shaped and is rotated, the grip no longer substantially conforms to the shape of the user""s palm and the user can again apply a compressive force to reshape the grip.
By providing a grip that is deformable and semi-resilient, the grip is more enjoyable and challenging to use than the grips or the base.-secured hand exercisers of the prior art.